Cutting insert with internal coolant delivery and cutting assembly using the same

ABSTRACT

A metalcutting insert that is useful in chipforming and material removal from a workpiece The metalcutting insert includes a metalcutting insert body, which includes a cutting edge having at least one discrete cutting location. The metalcutting insert body further contains a distinct interior coolant passage communicating with the discrete cutting location. The distinct interior coolant passage has a coolant passage inlet defining a coolant passage inlet cross-sectional area, a coolant passage discharge defining a coolant passage discharge cross-sectional area, and an axial coolant passage length. The distinct interior coolant passage defines a coolant flow cross-sectional area along the axial coolant passage length thereof. The coolant passage inlet cross-sectional area is substantially the same as the coolant passage discharge cross-sectional area. The geometry of the coolant flow area changes along the axial coolant passage length.

This patent application is a continuation-in-part of pending U.S. patentapplication Ser. No. 11/940,394 filed on Nov. 15, 2007 for MILLINGCUTTER AND MILLING INSERT WITH CORE AND COOLANT DELIVERY by Paul D.Prichard and Linn R. Andras, which is a continuation-in-part ofco-pending U.S. patent application Ser. No. 11/654,833 filed on Jan. 18,2007 for MILLING CUTTER AND MILLING INSERT WITH COOLANT DELIVERY by PaulD. Prichard and Linn R. Andras. Applicants hereby claim the benefit ofthe priority of the above two above-mentioned pending United StatesPatent Application, i.e., U.S. patent application Ser. No. 11/940,394filed on Nov. 15, 2007 and U.S. patent application Ser. No. 11/654,833filed on Jan. 18, 2007. Applicants further hereby incorporate byreference herein the entirety of each of said two mentioned pendingUnited States Patent Application, i.e., U.S. patent application Ser. No.11/940,394 filed on Nov. 15, 2007 and U.S. patent application Ser. No.11/654,833 filed on Jan. 18, 2007.

BACKGROUND OF THE INVENTION

The invention relates to a cutting insert, which has internal coolantdelivery, and an assembly using the cutting insert for use in thechipforming removal of material from a workpiece. More specifically, theinvention pertains to a cutting insert, as well as an assembly using thecutting insert, used for chipforming material removal operations whereinthere is enhanced delivery of coolant adjacent the interface between thecutting insert and the workpiece (i.e., the insert-chip interface) todiminish excessive heat at the insert-chip interface.

In a chipforming material removal operation (e.g., a milling operation,a turning operation, and the like), heat is generated at the interfacebetween the cutting insert and the location where the chip is removedfrom the workpiece (i.e., the insert-chip interface). It is well-knownthat excessive heat at the insert-chip interface can negatively impactupon (i.e., reduce or shorten) the useful tool life of the cuttinginsert. As can be appreciated, a shorter useful tool life increasesoperating costs and decreases overall production efficiency. Hence,there are readily apparent advantages connected with decreasing the heatat the insert-chip interface.

U.S. Pat. No. 6,053,669 to Lagerberg for CHIP FORMING CUTTING INSERTWITH INTERNAL COOLING discusses the importance of reducing the heat atthe insert-chip interface. Lagerberg mentions that when the cuttinginsert is made from cemented carbide reaches a certain temperature, itsresistance to plastic deformation decreases. A decrease in plasticdeformation resistance increases the risk for breakage of the cuttinginsert. U.S. Pat. No. 5,775,854 to Wertheim for METAL CUTTING TOOLpoints out that a rise in the working temperature leads to a decrease inhardness of the cutting insert. The consequence is an increase in wearof the cutting insert.

Other patent documents disclose various ways to or systems to delivercoolant to the insert-chip interface. For example, U.S. Pat. No.7,625,157 to Prichard et al. for MILLING CUTTER AND MILLING INSERT WITHCOOLANT DELIVERY pertains to a cutting insert that includes a cuttingbody with a central coolant inlet. The cutting insert further includes apositionable diverter. The diverter has a coolant trough, which divertscoolant to a specific cutting location. U.S. Patent ApplicationPublication No. US 2008-0175678 A1 to Prichard et al. for METAL CUTTINGSYSTEM FOR EFFECTIVE COOLANT DELIVERY pertains to a cutting insert thatfunctions in conjunction with a top piece and/or a shim to facilitatedelivery of coolant to a cutting location.

U.S. Pat. No. 6,045,300 to Antoun for TOOL HOLDER WITH INTEGRAL COOLANTPASSAGE AND REPLACEABLE NOZZLE discloses using high pressure and highvolume delivery of coolant to address heat at the insert-chip interface.U.S. Pat. No. 6,652,200 to Kraemer for a TOOL HOLDER WITH COOLANT SYSTEMdiscloses grooves between the cutting insert and a top plate. Coolantflows through the grooves to address the heat at the insert-chipinterface. U.S. Pat. No. 5,901,623 to Hong for CRYOGENIC MACHININGdiscloses a coolant delivery system for applying liquid nitrogen to theinsert-chip interface.

It is readily apparent that in a chipforming and material removaloperation, higher operating temperatures at the insert-chip interfacecan have a detrimental impact on the useful tool life through prematurebreakage and/or excessive wear. It would be highly desirable to providea cutting insert used for chipforming material removal operationswherein there is an improved delivery of coolant to the interfacebetween the cutting insert and the workpiece (i.e., the insert-chipinterface), which is the location on the workpiece where the chip isgenerated). There would be a number of advantages connected with theimproved delivery of coolant to the insert-chip interface.

In a chipforming material removal operation, the chip generated from theworkpiece can sometimes stick (e.g., through welding) to the surface ofthe cutting insert. The build up of chip material on the cutting insertin this fashion is an undesirable occurrence that can negatively impactupon the performance of the cutting insert, and hence, the overallmaterial removal operation. It would be highly desirable to provide acutting insert used for chipforming material removal operations whereinthere is enhanced delivery of coolant to the insert-chip interface so asto result in enhanced lubrication at the insert-chip interface. Theconsequence of enhanced lubrication at the insert-chip interface is adecrease in the tendency of the chip to stick to the cutting insert.

In a chipforming material removal operation, there can occur instancesin which the chips do not exit the region of the insert-chip interfacewhen the chip sticks to the cutting insert. When a chip does not exitthe region of the insert-chip interface, there is the potential that achip can be re-cut. It is undesirable for the milling insert to re-cut achip already removed from the workpiece. A flow of coolant to theinsert-chip interface will facilitate the evacuation of chips from theinsert-chip interface thereby minimizing the potential that a chip willbe re-cut. It would be highly desirable to provide a cutting insert usedfor chipforming material removal operations wherein there is enhanceddelivery of coolant to the insert-chip interface to reduce the potentialthat a chip will be re-cut. The consequence of enhanced flow of coolantto the insert-chip interface is better evacuation of chips from thevicinity of the interface with a consequent reduction in the potentialto re-cut a chip.

A number of factors can impact the extent of the coolant delivered tothe insert-chip interface. For example, the size of the structure thatconveys the coolant to the cutting insert can be a limiting factor onthe extent of coolant supplied to the cutting insert. Thus, it would behighly desirable to provide supply holes that are equal to or largerthan the inlets in the cutting insert to maximize the flow of thecoolant to the cutting insert. It would be highly desirable to provide acutting insert in which two or more coolant channels convey coolant to asingle discrete cutting location. Further, in order to customize thedelivery of coolant, the use of irregular coolant channels and variableareas of the inlet and the discharge in the cutting insert which allowfor such customization. One such feature is to provide for a range ofdiversion angles of the coolant, which can range between about 10degrees and about 60 degrees

In order to enhance delivery of coolant, it is advantageous to providefor the coolant to enter the cutting insert through the holder. This caninclude the use of an external coolant supply or an internal coolantsupply

In reference to the manufacturing of a cutting insert, there can beadvantages in using multiple pieces, which together form the cuttinginsert. For example, in some instances a cutting insert formed from abase, which presents the cutting edge, and a core can result in enhancedlongevity because only the base need to changed after reaching the endof the useful tool life. In such an arrangement, the core is detachablyjoins to the base whereby the core is re-used when the base wears out.The base and core can join together via co-sintering, brazing and/orgluing. As an alternative, the base and core can contact one anotherwithout joining together as an integral member, but remain separatecomponents even though in close contact. In addition, to enhanceperformance, the base and the core can be from the same or dissimilarmaterials depending upon the specific application.

When the preferred embodiment of the cutting insert presents a roundgeometry, certain advantages can exist. For example, when the cuttinginsert has a round geometry, the assembly of multiple components, e.g.,a base and a core, does not need indexing. A round cutting insert is nothanded so it can be used in left, right and neutral. In profile turning,up to 50% of the round cutting insert can function as the cutting edge.A round cutting insert is also available to engage an anti-rotationfeature.

SUMMARY OF THE INVENTION

In one form thereof, the invention is a metalcutting insert that isuseful in chipforming and material removal from a workpiece. Themetalcutting insert includes a metalcutting insert body, which includesa cutting edge having at least one discrete cutting location. Thecutting insert body further contains a distinct interior coolant passagecommunicating with the discrete cutting location. The distinct interiorcoolant passage has a coolant passage inlet defining a coolant passageinlet cross-sectional area, a coolant passage discharge defining acoolant passage discharge cross-sectional area, and an axial coolantpassage length. The distinct interior coolant passage defines a coolantflow cross-sectional area along the axial coolant passage lengththereof. The coolant passage inlet cross-sectional area is substantiallythe same as the coolant passage discharge cross-sectional area. Thegeometry of the coolant flow cross-sectional area changes along theaxial coolant passage length.

In another form thereof, the invention is a metalcutting assembly thatis useful in chipforming and material removal from a workpiece wherein acoolant source supplies coolant to the metalcutting assembly. Themetalcutting assembly comprises a holder that has a pocket wherein thepocket presents a flat surface containing a coolant port, which has acoolant port cross-sectional area, in communication with the coolantsource. The pocket receives a metalcutting insert. The metalcuttinginsert includes a metalcutting insert body, which includes a cuttingedge having at least one discrete cutting location. The metalcuttinginsert body further contains a distinct interior coolant passagecommunicating with the discrete cutting location. The distinct interiorcoolant passage has a coolant passage inlet defining a coolant passageinlet cross-sectional area, a coolant passage discharge defining acoolant passage discharge cross-sectional area, and an axial coolantpassage length. The distinct interior coolant passage defines a coolantflow cross-sectional area along the axial coolant passage lengththereof. The coolant passage inlet cross-sectional area is substantiallythe same as the coolant passage discharge cross-sectional area. Thegeometry coolant flow cross-sectional area changes along the axialcoolant passage length.

BRIEF DESCRIPTION OF THE DRAWINGS

The following is a brief description of the drawings that form a part ofthis patent application:

FIG. 1 is an isometric view of one specific embodiment of a millingcutter assembly wherein the milling cutter assembly has a milling cutterbody that carries a plurality of cutting inserts, which in this specificembodiment is five cutting inserts wherein a pocket carries a single oneof the cutting inserts;

FIG. 1A is a front view of one of the pockets of the milling cutterassembly of FIG. 1 wherein the pocket does not have the cutting inserttherein;

FIG. 2 is an isometric view of a specific embodiment of a KM® holderbody that carries a cutting insert in a pocket and wherein the cuttinginsert is not in the pocket, and KM is a registered trademark ofKennametal Inc. of Latrobe, Pa. 15650;

FIG. 2A is a top view of the pocket, which does not have the cuttinginsert therein, of the KM® holder body of FIG. 2;

FIG. 3 is an isometric view of a specific embodiment of a screw-ontoolholder body that carries a cutting insert in a pocket and whereinthe cutting insert is not in the pocket, and wherein there isillustrated in schematic form the connection between the coolant sourceand the coolant discharge port in the flat surface of the pocket;

FIG. 3A is a top view of the pocket, which does not contain the cuttinginsert therein of the screw-on toolholder body of FIG. 3;

FIG. 4 is an isometric view of the base member of the cutting insertshowing the rake surface and the flank surface of the base member;

FIG. 4A is an enlarged view of a portion of the base member of FIG. 4showing in detail the channel defined between two ribs;

FIG. 5 is an isometric view of the base member of the cutting insertshowing the bottom surface and the flank surface of the cutting insert;

FIG. 6 is an isometric view of the core member of the cutting insertshowing the top surface and the side surface of the core member;

FIG. 7 is an isometric view of the core member of the cutting showingthe bottom surface and the side surface of the core member;

FIG. 7A is an isometric view of the base member and the core memberwherein the core member is exploded away from the base member;

FIG. 8 is an isometric view of the assembly of the base member and thecore member of the cutting insert showing the rake surface and flanksurface of the cutting insert;

FIG. 9 is an isometric view of the bottom surface of the cutting insert;

FIG. 10 is an enlarged view of the portion of the bottom surface showinga location of the joinder of the base member and the core member;

FIG. 11 is a bottom view of the specific embodiment of the cuttinginsert of FIG. 5;

FIG. 12 is a side view of the specific embodiment of the cutting insertof FIG. 5;

FIG. 13 is an isometric view with a part of the cutting insert and theholder removed to show the delivery of coolant to a discrete cuttinglocation; and

FIG. 14 is a top view of a specific embodiment of the cutting insert;

FIG. 14A is an enlarged view of a portion of the cross-sectional viewFIG. 14B wherein there is shown the distinct interior coolantpassageway;

FIG. 14B is a cross-sectional view of the cutting insert of FIG. 14taken along section line 14B-14B;

FIG. 15 is a cross-sectional view of the cutting insert showing thedistinct interior coolant passageway taken along section line 15-15 ofFIG. 14B;

FIG. 15A is an enlarged view of a part of the cross-section of FIG. 15in the circle designated 15A showing the geometry of the interiorcoolant passage;

FIG. 16 is a cross-sectional view of the cutting insert showing thedistinct interior coolant passageway taken along section line 16-16 ofFIG. 14B;

FIG. 16A is an enlarged view of a part of the cross-section of FIG. 16in the circle designated 16A showing the geometry of the interiorcoolant passage;

FIG. 17 is a cross-sectional view of the cutting insert showing thedistinct interior coolant passageway taken along section line 17-17 ofFIG. 14B wherein section line 17-17 is taken at an angle “M” equal to30.18 degrees;

FIG. 18 is a cross-sectional view of the cutting insert showing thedistinct interior coolant passageway taken along section line 18-18 ofFIG. 14B wherein section line 18-18 is taken at an angle “N” equal to50.10 degrees;

FIG. 19A is a top view illustrating the cutting insert in the pocket inone cutting position wherein the coolant inlets communicate with thecoolant source and the abutment member engages the flank surface;

FIG. 19B is a top view illustrating the cutting insert in the pocket inan indexed cutting position wherein the coolant inlets communicate withthe coolant source and the abutment member engages the flank surface;

FIG. 20 is a top view of the cutting insert showing the coolant flow;and

FIG. 21 is a cross-sectional view of the cutting insert showing the flowof coolant through the interior coolant passage.

DETAILED DESCRIPTION

Referring to the drawings, there should be an appreciation that thecutting insert of the invention, as well as the cutting assembly of theinvention, can operate in a number of different applications. Thecutting insert, which has internal coolant delivery, is for use in thechipforming removal of material from a workpiece. In this respect, thecutting insert is for use in a chipforming material removal operationwherein there is enhanced delivery of coolant adjacent the interfacebetween the cutting insert and the workpiece (i.e., the insert-chipinterface) to diminish excessive heat at the insert-chip interface.

The enhanced delivery of coolant to the insert-chip interface leads tocertain advantages. For example, enhanced delivery of coolant to theinsert-chip interface results in enhanced lubrication at the insert-chipinterface which decreases the tendency of the chip to stick to thecutting insert. Further, enhanced flow of coolant to the insert-chipinterface leads to better evacuation of chips from the vicinity of theinterface with a consequent reduction in the potential to re-cut a chip.

As will be made apparent from the description hereinafter, the nature ofthe coolant dispersion or spray is such that it is continuous betweenthe adjacent so-called activated interior coolant passages. The coolantactually exits the activated coolant passages in the form of acontinuous cone of coolant, By providing such a coolant dispersion, thecutting insert achieves enhanced delivery of coolant to the insert-chipinterface.

There should also be an appreciation that the interior coolant passagedischarge has an orientation whereby the coolant impinges beneath thechip surface. Such an orientation of the coolant enhances the coolingproperties, which enhances the overall performance of the cuttinginsert.

The description herein of specific applications should not be alimitation on the scope and extent of the use of the cutting insert.

In the chipforming material removal operation, the cutting insert 150engages a workpiece to remove material from a workpiece typically in theform of chips. A material removal operation that removes material fromthe workpiece in the form of chips typically is known by those skilledin the art as a chipforming material removal operation. The book MachineShop Practice [Industrial Press Inc., New York, N.Y. (1981)] byMoltrecht presents at pages 199-204 a description, inter alia, of chipformation, as well as different kinds of chips (i.e., continuous chip,discontinuous chip, segmental chip). Moltrecht reads [in part] at pages199-200, “When the cutting tool first makes contact with the metal, itcompresses the metal ahead of the cutting edge. As the tool advances,the metal ahead of the cutting edge is stressed to the point where itwill shear internally, causing the grains of the metal to deform and toflow plastically along a plane called the shear plane . . . . When thetype of metal being cut is ductile, such as steel, the chip will comeoff in a continuous ribbon . . . ”. Moltrecht goes on to describeformation of a discontinuous chip and a segmented chip.

As another example, the text found at pages 302-315 of the ASTE ToolEngineers Handbook, McGraw Hill Book Co., New York, N.Y. (1949) providesa lengthy description of chip formation in the metal cutting process. Atpage 303, the ASTE Handbook makes the clear connection between chipformation and machining operations such as turning, milling anddrilling. The following patent documents discuss the formation of chipsin a material removal operation: U.S. Pat. No. 5,709,907 to Battaglia etal. (assigned to Kennametal Inc.), U.S. Pat. No. 5,722,803 to Battagliaet al. (assigned to Kennametal Inc.), and U.S. Pat. No. 6,161,990 toOles et al. (assigned to Kennametal Inc.).

Referring to the drawings, FIG. 1 is an isometric view that shows amilling cutter assembly generally designated as 40. Milling cutterassembly 40 has a milling cutter body 42 with a central milling cutterbody portion 44. A plurality of lobes 46 extend in a radial outwardfashion from the central milling cutter body portion 44. Each one of thelobes 46 has a radial inner edge 46 and a radial outer edge 48. Eachlobe 46 further has a distal end 47.

At the distal end 47, each one of the lobes 46 contains a pocket 54 thathas a flat surface 56. The flat surface 56 is generally circular and hasa circumferential edge 57. An upstanding wall 58 is at one end of theflat surface 56 wherein the upstanding wall 58 extends about a portionof the circumferential edge 57.

The flat surface 56 further contains an arcuate opening (arcuate notch)60 that extends in a parallel manner for a portion of thecircumferential edge 57. There is a coolant discharge port 62 incommunication with the arcuate opening 60. The coolant discharge port 62is in fluid communication with a coolant passage, which has a coolantentrance port. Coolant from a coolant source enters the coolant passagethrough the coolant entrance port and travels so to exit at the coolantdischarge port into the arcuate opening 60. Coolant exiting into thearcuate opening 60 then passes into the cutting insert 150, as will beset forth in more detail hereinafter. The arcuate opening 60 extendsabout 90 degrees so to communicate with two adjacent interior coolantpassages. The specific structure of the coolant source, the coolantpassage, and the coolant entrance port is not illustrated, but issubstantially the same as corresponding structure illustrated anddiscussed in conjunction with the screw-on toolholder 114.

Referring to FIG. 1A, as mentioned hereinabove, the milling cutter body42 has a pocket 54 and an adjacent upstanding wall 58. The upstandingwall 58 includes an anti-rotation abutment 70, which extends in a radialinward fashion from the upstanding wall 58. The anti-rotation abutment70 further has a peripheral abutment edge 72. As will be described inmore detail hereinafter, the peripheral abutment edge 72 exhibits ageometry to engage the cutting insert 150 whereby the anti-rotationabutment 70 prevents rotation of the cutting insert 150 when in thepocket 54. The anti-rotation abutment 70 and its cooperation with thecutting insert are along the lines of the structure shown and describedin U.S. Pat. No. 6,238,133 B1 to DeRoche et al. for ANTI-ROTATIONMOUNTING MECHANISM FOR ROUND CUTTING INSERT.

The cutting insert 150 can be used in conjunction with holders otherthan the milling cutting 40 described above. For example and referringto FIGS. 2 and 2A, one can use the cutting insert 150 in conjunctionwith a KM® holder 80. The KM® holder 80 has a distal end 82 and aproximate end 84. The KM® holder 80 further has a pocket 86, which has aflat surface 88, at the distal end 82 thereof. The flat surface 88 has acircular geometry and a circumferential edge 89.

An upstanding wall 90 is adjacent to the flat surface 88. The upstandingwall 90 extends for a portion of the circumferential edge 89 of the flatsurface 88. The flat surface 88 further contains an arcuate opening 92,which is in communication with a coolant discharge port 94. The flatsurface 88 further has a threaded aperture 96, which facilitatesattachment of the cutting insert 150 to the KM® holder 80, therein.

Although not shown in the drawings, the KM® holder 80 further has acoolant passage, which has a coolant entrance port. The coolant entranceport is in communication with a coolant source. As described in moredetail hereinafter, the coolant passes from the coolant source throughthe coolant entrance port into the coolant passage and exits the coolantpassage via the coolant discharge port 94 into the arcuate opening 92.Coolant then travels from the arcuate opening 92 into the cutting insert150. The arcuate opening extends about 180 degrees so to communicatewith three adjacent interior coolant passages.

The KM® holder 80 further includes an anti-rotation abutment 104 thatextends in a radial inward fashion from the upstanding wall 90. Theanti-rotation abutment 104 has a peripheral abutment surface 106. Aswill be the subject of a discussion hereinafter, the peripheral abutmentsurface 106 presents a geometry that engages the cutting insert 150 toprevent rotation of the cutting insert 150 when in the pocket 86.

As still another example of a holder suitable for use with the cuttinginsert 150, FIGS. 3 and 3A illustrate a screw-on toolholder 114, whichhas a toolholder body 116. Toolholder body 116 has a distal end 118 anda proximate end 120. The toolholder body 116 has a pocket 122 at thedistal end 118 thereof. The pocket 122 presents a flat surface 124 thatpresents a generally cylindrical shape with a peripheral circumferentialedge 125. There is an upstanding wall 126 along a portion of theperipheral circumferential edge 125 of the flat surface 124.

The flat surface 124 further contains a threaded aperture 132, whichfacilitates attachment of the cutting insert 150 to the screw-ontoolholder 114, therein.

The flat surface 124 contains an arcuate opening 128, which communicateswith a coolant discharge port 130. The screw-on toolholder 114 furtherhas a coolant passage 134, which has a coolant entrance port 135 and apair of coolant discharge ports 136 and 137. The coolant discharge ports136, 137 are in communication with a coolant source. As described inmore detail hereinafter, the coolant passes from the coolant source 138through the coolant entrance port 135 into the coolant passage 134 andexits the coolant discharge passage 134 via the coolant discharge ports136, 137. Coolant then passes into the arcuate opening 128, and, as willbe described in more detail, into the cutting insert 150. The arcuateopening extends about 180 degrees so to communicate with three adjacentinterior coolant passages.

There should be an appreciation that any one of a number of differentkinds of fluid or coolant are suitable for use in the cutting insert.Broadly speaking, there are two basic categories of fluids or coolants;namely, oil-based fluids which include straight oils and soluble oils,and chemical fluids which include synthetic and semisynthetic coolants.Straight oils are composed of a base mineral or petroleum oil and oftencontain polar lubricants such as fats, vegetable oils, and esters, aswell as extreme pressure additives of chlorine, sulfur and phosphorus.Soluble oils (also called emulsion fluid) are composed of a base ofpetroleum or mineral oil combined with emulsifiers and blending agentsPetroleum or mineral oil combined with emulsifiers and blending agentsare basic components of soluble oils (also called emulsifiable oils).The concentration of listed components in their water mixture is usuallybetween 30-85%. Usually the soaps, wetting agents, and couplers are usedas emulsifiers, and their basic role is to reduce the surface tension.As a result they can cause a fluid tendency to foam. In addition,soluble oils can contain oiliness agents such as ester, extreme pressureadditives, alkanolamines to provide Òreserve alkalinityÓ, a biocide suchas triazine or oxazolidene, a defoamer such as a long chain organicfatty alcohol or salt, corrosion inhibitors, antioxidants, etc.Synthetic fluids (chemical fluids) can be further categorized into twosubgroups: true solutions and surface active fluids. True solutionfluids are composed essentially of alkaline inorganic and organiccompounds and are formulated to impart corrosion protection to water.Chemical surface-active fluids are composed of alkaline inorganic andorganic corrosion inhibitors combined with anionic non-ionic wettingagents to provide lubrication and improve wetting ability.Extreme-pressure lubricants based on chlorine, sulfur, and phosphorus,as well as some of the more recently developed polymer physicalextreme-pressure agents can be additionally incorporated in this fluids.Semisynthetics fluids (also called semi-chemical) contains a loweramount of refined base oil (5-30%) in the concentrate. They areadditionally mixed with emulsifiers, as well as 30-50% of water. Sincethey include both constituents of synthetic and soluble oils,characteristics properties common to both synthetics and water solubleoils are presented.

The toolholder body 116 further includes an anti-rotation abutment 140that extends in a radial inward fashion from the upstanding wall 126.The anti-rotation abutment 140 has a peripheral abutment surface 142.The peripheral abutment surface 142 has a geometry that engages thecutting insert 150 to prevent rotation of the cutting insert 150 when inthe pocket 122.

Referring to the remainder of the drawings, the following is adescription of a preferred specific embodiment of the cutting insert 150(see FIGS. 8 and 9) that is suitable for use with any one of theholders, i.e., milling cutter body 42, KM® holder 80, and screw-ontoolholder 114. Cutting insert 150 is useful in chipforming materialremoval from a workpiece wherein a coolant source supplies coolant tothe cutting insert. The cutting insert 150 includes a cutting insertbody 151 (see FIG. 8) that comprises a base member 152 and a core member154. As will be described in more detail hereinafter, the base member152 and the core member 154 function together to form the cutting insertbody 151. As will become apparent from the discussion hereinafter, thebase member and core member can be joined together to form an integralpiece or can be compressed together maintaining their individualseparate and distinct nature.

The components, i.e., the base member 152 and the core member 154, ofthe cutting insert 150 may be made from one of any number of materialsthat are suitable for use as a cutting insert. The following materialsare exemplary materials useful for a cutting insert: tool steels,cemented carbides, cermets or ceramics. The specific materials andcombinations of materials depend upon the specific application for thecutting insert. Applicants contemplate that the base member and the coremember may be made from different materials.

In reference to tool steels, the following patent documents disclosetool steels suitable for use as a cutting insert: U.S. Pat. No.4,276,085 for High speed Steel, U.S. Pat. No. 4,880,461 for Superhardhigh-speed tool steel, and U.S. Pat. No. 5,252,119 for High Speed ToolSteel Produced by Sintered Powder and Method of Producing the Same. Inreference to cemented carbides, the following patent documents disclosecemented carbides suitable for use as a cutting insert: U.S. PatentApplication Publication No. US2006/0171837 A1 for a Cemented CarbideBody Containing Zirconium and Niobium and Method of Making the Same,U.S. Reissue Pat. No. 34,180 for Preferentially Binder Enriched CementedCarbide Bodies and Method of Manufacture, and U.S. Pat. No. 5,955,186for a Coated Cutting Insert with A C Porosity Substrate HavingNon-Stratified Surface Binder Enrichment. In reference to cermets, thefollowing patent documents disclose cermets suitable for use as acutting insert: U.S. Pat. No. 6,124,040 for Composite and Process forthe Production Thereof, and U.S. Pat. No. 6,010,283 for a Cutting Insertof a Cermet Having a Co—Ni—Fe Binder. In reference to ceramics, thefollowing patent documents disclose ceramics suitable for use as acutting insert: U.S. Pat. No. 5,024,976 for an Alumina-zirconia-siliconcarbide-magnesia Ceramic Cutting Tools, U.S. Pat. No. 4,880,755 for aSiAlON Cutting Tool Composition, U.S. Pat. No. 5,525,134 for a siliconNitride Ceramic and Cutting Tool made Thereof, U.S. Pat. No. 6,905,992for a Ceramic Body Reinforced with Coarse Silicon Carbide Whiskers andMethod for Making the Same, and U.S. Pat. No. 7,094,717 for a SiAlONContaining Ytterbium and Method of Making.

Referring to the base member 152, as especially the illustrations of thebase member 152 in FIGS. 4, 4A and 5, the base member 152 includes arake surface 156 and a flank surface 158. Since the core member 154 fitswithin the base member 52 to form the cutting insert 150, the flanksurface 158 of the base member 152 is the flank surface of the cuttinginsert 150. In a like fashion, due to the dimensioning and positioningof the core member 154 relative to the base member 152, the rake surface156 of the base member 152 provides the operative rake surface of thecutting insert 150.

The intersection of the rake surface 156 and the flank surface 158 forma cutting edge 160, which in this embodiment is a generally roundcutting edge. As will be described in more detail hereinafter, thecutting edge 160 presents a plurality of discrete cutting locations. Inthis embodiment, there are six discrete cutting locations 161A through161F. The discrete cutting locations (161A-161F) are spaced apart about60 degrees apart. Further, each discrete cutting location (161A-161F) islocated mid-way between each pair of adjacent ribs 170.

The rake surface 156 of the base member 152 has a radial outward surface162, which is radial inward of the cutting edge 160 and extends aroundthe entire circumference of the rake surface 156. Located radial inwardof the radial outward surface 162 is a first transition surface 164 andlocated radial inward of the first transition surface 164 is a secondtransition surface 166. Each one of the first and second transitionsurfaces moves toward the bottom of the cutting insert as it moves in aradial inward direction. The second transition surface 166 blends intoeither a channel 168 or a rib 170.

There should be an appreciation that the surfaces, i.e., radial outwardsurface 162, the first transition surface 164, and the second transitionsurface 166, may exhibit any one of a number of different geometries orsurface configurations. An objective of these surfaces is to provide atransition between the cutting edge 160 and the interior portion of thebase member 152 comprising the channels 168 and the ribs 170. Further, aparticular specific geometry may be effective to enhance a chipbreakingfeature of the cutting insert. A particular specific geometry may alsobe effective to enhance coolant delivery to the insert-chip interface ascoolant can impinge on this area of the cutting insert.

Referring to FIG. 4A, which is an enlargement of a section of FIG. 4,each one of the channels 168 has a pair of opposite channel peripheralsurfaces, i.e., channel peripheral surface 172 and a channel peripheralsurface 174. Each channel 168 further has a central trough 176. Eachadjacent rib 170 has a radial inward barrier 180 and an opposite radialinward barrier 181, which define lateral boundaries for the channel 168.Each one of the ribs 170 also has a peripheral contact surface 182.

The base member 152 further defines a central core reception aperture186. The central core reception aperture 186 receives the core member154. There is a discussion hereinafter of the assembly of the basemember 152 and the core member 154.

The base member 152 also has a flank surface 158. The flank surface 158has a cylindrical flank surface portion 200 adjacent to the rake surface156. The cylindrical flank surface portion 200 extends toward the bottomsurface a selected distance, at which point it transitions into agenerally frusto-conically shaped surface portion (see bracket 202).

The generally frusto-conically shaped surface portion 202 presents asinusoidal-shaped geometry wherein there are a plurality ofsinusoidal-shaped valleys or scallops 206. Each one of thesinusoidal-shaped valleys 206 has an opposite side 208, another oppositeside 210, and an arcuate mediate portion 212. For each sinusoidal-shapedvalley 206, the circumferential width increases from the top to thebottom of the base member 152. Between each one of the sinusoidal-shapedvalleys 206, there are sinusoidal-shaped islands 220. Eachsinusoidal-shaped island 220 has opposite sides 221, 222 and an arcuatemediate portion 223. For each sinusoidal-shaped island 220, thecircumferential width decreases from the top to the bottom of the basemember 152.

Each sinusoidal-shaped valley 206 defines a depression that presents anarcuate surface. As will be discussed hereinafter, the sinusoidal-shapedvalley 206 can cooperate with an anti-rotation abutment whereby theabutment engages the depression of the sinusoidal-shaped valley 206 toprevent rotation of the cutting insert 150 when in the pocket of theholder. There should be an appreciation that the geometry of the flanksurface does not have to present the sinusoidal-shaped scallops. Theflank surface can take on other geometries such as, for example, asmooth surface without scallops or depressions.

The base member 152 further has a bottom surface 226. The bottom surface226 presents a sinusoidal-shaped circumferential edge 228. Thesinusoidal-shaped circumferential edge 228 has a plurality of peaks 230Athrough 230F and a plurality of valleys 232A through 232F.

The bottom surface 226 of the base member 152 further contains notches238A through 238F and lands 240A through 240F. These notches (238A-238F)and lands (240A-240F) define the profile of the edge at the terminationof the central core reception aperture 186.

Referring to the structure of the core member 154, and especially FIGS.6 and 7, the core member 154 comprises a top end 244 and a bottom end246. Adjacent the top end 244 is a generally circular section 248, andadjacent the bottom end 246 is an integral generally frusto-conicalsection 250, which extends from the generally circular section 248 viaan arcuate transition 251. At the top end 244 there is a radial outertop surface 252, which has a circumferential outer edge 254. Locatedradial inward of the radial outer top surface 252 is a radial inner edge256.

Referring to the interior surface of the integral generallyfrusto-conical section 250, moving in a direction toward the bottom end246, there is an interior transition surface 258 that blends into aninterior cylindrical surface 262. Referring to the exterior surface ofthe integral generally frusto-conical section 250, there is an arcuateexterior surface 264 and a frusto-conical exterior surface 266. There isa bottom cylindrical surface 268, which has a radial outercircumferential edge 270, at the bottom end 246.

As will become apparent from the description below, the cutting insertbody 151 contains a plurality of distinct interior coolant passages 300(see FIG. 14) formed between the base member 152 and the core member154. As described in more detail, When attached to the pocket of aholder, an adjacent pair of the distinct interior coolant passages 300corresponds to each one of the discrete cutting locations.

In order to form the complete cutting insert 150, such as, for exampleillustrated in FIG. 8, the base member 152 and the core member 154 jointogether. FIG. 8A illustrates the core member 154 exploded away from andin alignment with the base member 152. The central core receptionaperture 186 of the base member 152 receives the core member 154 so theexterior surface of the core member 154 contacts selected areas of thebase member 152. More specifically, the portions of the arcuate exteriorsurface 264 and the frusto-conical exterior surface 266 contacts thearcuate contact surface 182 of each one of the ribs 168. In thedrawings, the contact surface 182 is shown cross-hatched.

The points of contact between the base member 152 and the core member154 are very secure. This very secure contact between the base member152 and the core member 154 is shows in FIG. 10 and in FIG. 15. Theextent of the contact is sufficiently secure be fluid-tight at thelocations of contact. The extent of the contact is secure enough so thecomponents do not separate during usage.

The contact between the base member and the core member can be throughactual joinder of these components together. One can accomplish thejoinder of the base member 152 and the core member 154 via any one of anumber of ways. For example, techniques such as, co-sintering, brazingand/or gluing are suitable. The specific technique may be particularlyapplicable to certain materials. For example, co-sintering may beapplicable to a situation in which the base member and the core memberare of the same material (e.g., tungsten carbide-cobalt material).Gluing may be applicable to a situation in which the materials for thebase member and the core member are dissimilar (e.g., a steel coremember and a tungsten carbide-cobalt base member). The contact can alsobe accomplished via compressing the component together while stillmaintaining theme to be separate and distinct from one another. Forexample, the cutting insert can be securely threaded to the holderwhereby there is a very strong surface-to-surface contact between thebase member and the core member due to the very tight connection betweenthe cutting insert and the holder. When the components are compressedtogether via tightening of the cutting insert to the holder, thesecomponents may be separated upon detachment of the cutting insert fromthe holder.

The choice of specific materials for the components is dependent uponthe particular applications for the cutting insert. The use ofceramic-ceramic or carbide-carbide or steel-carbide combinations of thecomponents provides the cutting insert with a variety of materialoptions. By doing so, the cutting insert has an expansive materialselection feature that allows for optimum customization of the cuttinginsert from the materials perspective.

As is apparent, the components, and hence the cutting insert, present around geometry. By using a round geometry, the assembly of multiplecomponents, e.g., a base and a core, does not need indexing toaccomplish. The absence of indexing or special alignment reduces themanufacturing costs and makes the assembly easier in contrast tocomponents that require special alignment. This is especially the casefor the core member. The core member has a generally cylindrical/conicalgeometry. It does not have exterior features that require specialalignment or orientation in the assembly to the base. Thus, the assemblyof the core to the base is easy and inexpensive as compared to theassembly of components, each of which have complex geometric features.

As mentioned above, the cutting insert 150 has a plurality of distinctinterior coolant passage 300. The following description of one interiorcoolant passage 300 is sufficient for a description of all such interiorcoolant passages 300.

In reference to each one of the interior coolant passages 300, selectedsurfaces on the base member 152 and on the core member 154 define theboundaries of the interior coolant passage 300. More specifically, someof the selected surfaces of the base member 152 are those that definethe channel 168, i.e., the channel peripheral surfaces 172, 174 and thecentral trough 176. Other selected surfaces of the base member 152include the radial inward barrier 178 of one rib 170 and the radialinward barrier 180 of an adjacent rib 170. In reference to the coremember 154, the exterior surface helps define the interior coolantpassage 300.

The interior coolant passage 300 has an interior coolant passagedischarge 302 and an interior coolant passage inlet 304. As is apparent,coolant enters the interior coolant passage 300 through the interiorcoolant passage inlet 304, travels through the interior coolant passage300, and then exits via the interior coolant passage discharge 302. Uponexiting the interior coolant passage 300, coolant sprays toward thediscrete cutting location in engagement with the workpiece.

FIG. 14 is a top view of the cutting insert 150 that provides areference point for the discussion of the interior coolant passage 300,especially the geometry of the interior coolant passage 300, in apreferred specific embodiment of the cutting insert 150. FIG. 14B is across-sectional view of the cutting insert 150 of FIG. 14 taken alongsection line 14B-14B of FIG. 14. FIG. 14A is an enlarged view of thesection in the circle 14A of FIG. 14B showing interior coolant passage300. As shown in FIG. 14B, the cross-sectional views FIGS. 15, 15A, 16,16A, 17 and 18 are taken at an orientation generally perpendicular tothe general direction of the coolant flow. The cross-sectional area canbe considered to be the coolant flow area at the particular locationalong the interior coolant passage.

In this preferred specific embodiment, it is apparent that the geometryof the coolant flow cross-sectional area of the interior coolant passage300 changes along the axial length of the interior coolant passage 300,i.e., the axial coolant passage length. Further, there should be anappreciation that the coolant flow cross-sectional area can vary toachieve a specific desired flow configuration or spray pattern at theinsert-chip interface. In this particular embodiment, the spray patternis of a continuous nature to present a continuous cone of coolant in thevicinity of the discrete cutting location. In this regard, FIG. 20illustrates in schematic form the coolant spray pattern (arrowsdesignated as “CF”) when two adjacent interior coolant passages areactivated, i.e., in communication with the coolant source, during amaterial removal operation.

Table I below sets forth the coolant flow areas at the locations shownby the cross-sections 15-15 through 18-18 in FIG. 14B for a specificembodiment of the cutting insert. The specific values in this table aremerely for a preferred specific embodiment and there is no intention tobe restrictive on the scope of the invention as defined by the appendedclaims. Table I also presents the distance each cross-section is fromthe interior coolant passage inlet 304. The reference letter “W”, “X”,“Y” and “Z” correspond to the locations of the cross-sections asindicated in Table I. More specifically, the distances “W”, “X”, “Y” and“Z” are at the locations where the cross-section line passes through theradial inward surface of the interior coolant passage 300.

TABLE I Values of Coolant Flow Area in Interior Coolant Flow PassageVertical Distance from the Interior Section Line Coolant PassageLocation Along Inlet (mm) Ratio to Inlet Interior Coolant [referenceletter Area (square Coolant Flow Passage from FIG. 14A] millimeters)Flow Area 15-15 0.36 [W] 2.3797 1.00 16-16 3.98 [X] 3.5104 1.48 17-175.07 [Y] 2.9650 1.24 18-18 5.55 [Z] 2.4473 1.03

Based on the data from Table I, the coolant passage inlet area issubstantially the same as the coolant passage discharge area, thecoolant flow area changes along the axial coolant passage length, andthe coolant passage inlet being smaller than the coolant port area. Inreference to the latter feature, in this preferred specific embodimentof the cutting insert, the coolant port to which it is in communicationhas a coolant port area equal to 7.06 square millimeters.

Referring to FIGS. 15A and 16A, the interior coolant passage can bedefined in cross-section by an arcuate radial inward surface 600, a pairof sides 602, 604, which move in a generally radial outward direction,and a pair of converging radial outward surfaces 606, 608, which joinone another at an apex 610. It is apparent from a comparison between thecoolant flow areas of FIG. 15A and FIG. 16A, the coolant flow area ofthe interior coolant passage 300 from the interior coolant passage inlet304 to the point at which cross-section 16-16 is taken increases. Thearcuate radial inward surface 600 widens to some extent, as does thelength of the pair of converging radial outward surfaces 606, 608, whichjoin one another at an apex 610. The pair of sides 602, 604 which movein a generally radial outward direction, remain somewhat constant inthis region of the interior coolant passage 300. The increase in thecoolant flow area occurs due to the increase in the width of the arcuateradial inward surface 600 and the consequent increase in dimensions ofthe pair of converging radial outward surfaces 606, 608, which join oneanother at an apex 610.

The coolant flow area increases to a lesser extent from the point ofcross-section 16-16 and cross-section 17-17. A comparison between thecoolant flow area at the points in the interior coolant passage 300shown by cross-section 16-16 and 17-17 show a further widening of theinterior coolant passage. The coolant flow area as shown in FIG. 18represents the coolant flow area of the interior coolant passagedischarge 302. It is apparent that overall, there is a lateral expansionand radial decrease of the interior coolant passage as it moves from theinlet to the discharge.

FIG. 15A represents the geometry of the interior coolant passage inlet304. FIG. 18 represents the geometry of the interior coolant passagedischarge 302. A comparison of these geometries shows that the geometryof the interior coolant passage inlet 304 is different from the geometryof the interior coolant passage discharge 302. This is the case eventhough the coolant passage inlet area is substantially the same as thecoolant passage discharge area.

Referring to FIG. 19 and FIG. 19A, in operation, the cutting insert isretained in the pocket of a holder such as, for example, the millingcutter 40. In a holder like the milling cutter 40, the cutting insert150 is maintained in the pocket by a screw that passes through thecutting insert and into the threaded aperture in the pocket. To securethe cutting insert in the pocket, the cutting insert has an orientationsuch that the anti-rotation abutment 70 engages the flank surface of thecutting insert. In this regard, the peripheral abutment edge 72 presentsa geometry that corresponds to the geometry of the sinusoidal-shapedvalley 206. This engagement creates an abutment that restricts therotational movement of the cutting insert when in the pocket.

To engage in cutting (i.e., material removal), the cutting insert 150 isin a condition whereby there is a selected one of the plurality ofdiscrete cutting locations engaging the workpiece. The arrow “DCL1” inFIG. 19A generally shows the selected discrete cutting location. When inthis condition, the corresponding pair of the distinct interior coolantpassages 300A and 300B communicate with the arcuate aperture throughcoolant passage inlets 304A and 304B, which is in turn, in communicationwith the coolant source through a coolant port.

Referring to FIG. 19A, the relative positioning between the cuttinginsert and the pocket shows the arcuate aperture is in fluidcommunication with the adjacent pair of interior coolant passage inlet304A and 304B. There is an appreciation that coolant from the coolantsource flows simultaneously into both the interior coolant passage 300Aand 300B whereby interior coolant passage 300A and 300B can beconsidered activated. It should be understood that the pocket couldinclude an arcuate aperture (or a like feature) that permits a trio ofinterior coolant passages to communicate simultaneously with the coolantsource.

Referring to FIG. 21, as one can appreciate, the coolant follows thesurfaces defining the interior coolant passage 300. As the coolantfollows the arcuate surface of the core, the coolant drives toward theinterior coolant passage discharge 302 in a radial outward direction.The coolant thus is flowing at the cutting edge as it exits the interiorcoolant passage discharge 302. By flowing in a radial outward direction,the coolant better functions to flood the cutting edge in engagementwith the workpiece. The coolant spray pattern shows a dispersion angleDA1, which is the angle relative to the axis parallel to the rakesurface of the cutting insert. There should be an appreciation that thedispersion angle can range between about 10 degrees and about 60degrees. A review of FIG. 13 shows the same feature that the coolantdisperses as it exits the interior coolant passage discharge.

Because of the nature of the geometry of the interior coolant passage,the dispersion of coolant leads to a continuous spray of coolant. FIG.20 is a schematic view that represents this continuous coolant spray.The continuous spray of coolant ensures that the insert-chip interfaceat the discrete cutting location experiences sufficient coolantflooding, and hence, sufficient coolant-caused cooling. As mentionedhereinbefore, a number of advantages exit due to the delivery ofsufficient coolant to the insert-chip interface.

Once the discrete cutting location has worn to a point where change isnecessary, the operator can index the cutting insert to the next cuttingposition. FIG. 19B shows the next cutting position. The arrow “DCL2” inFIG. 19B generally shows the next selected discrete cutting location.When in the new position, the corresponding pair of the distinctinterior coolant passages (300B and 300C) communicate with the coolantsource via the coolant passage inlets 304B and 304C to deliver coolantto the cutting insert 150 at the selected discrete cutting location.Thus, coolant is supplied to the insert-chip interface corresponding tothe new discrete cutting location.

Test results were conducted to compare a specific embodiment of theinventive (through coolant) cutting insert against a commercial cuttinginsert (standard cutting insert) made and sold by Kennametal Inc. ofLatrobe, Pa. 15650. Both cutting inserts were made from the same gradeof cemented (cobalt) tungsten carbide, the same insert style (except forthe through coolant feature of the inventive cutting insert) and thesame edge preparation wherein the ISO designation for the cuttinginserts including the edge preparation was RCGX64SFG. The test resultsare set forth in Table II below in the number of passes before thecutting insert became worn to the following point wherein the failurecriteria was either 0.015 inch of maximum flank wear or a maximum rakeface chip of 0.030 inch, whichever occurred first.

TABLE II Test Results (in Number of Passes) from Cutting TestInsert/Result Rep. 1 Rep. 2 Rep. 3 Std. Dev. Average Standard 6.00 3.004.00 1.53 4.33 Cutting Insert Inventive or 8.00 13.00 13.00 2.89 11.33Through Coolant Cutting Insert

Other test parameters are set forth below. Workpiece material: Ti6Al4V.Insert edge style=round with the iC=0.750 inches; the cutter diameterwas 3.00 inches; the number of inserts per cutter was one and the lengthof the pass was 12 inches. The cutting speed was Vc=150 feet/minute;RPM=202; the true chip load=0.006 inch/tooth; prog. chip load=0.010inch/tooth; axial depth of cut=0.15 inches; radial depth of cut=2.000inches; feed rate=2.020 inches per minute. The machine was a Mazak FJV;the coolant was wet; the coolant type was Syntilo® [Syntilo is aregistered trademark of Castrol Limited, Wiltshire England]; the coolantpressure=1000 psi; the concentration=12.0%; and the MMR(inch²/min)=0.606.

As is apparent from the test results, the inventive cutting insertexperienced substantial improvement over the commercial cutting insert.The number of passes before a change was necessary increased from anaverage of 4.33 to an average of 11.33. This is an increase in thenumber of passes of about 261 percent, which is greater than 250percent.

It is readily apparent that the present cutting insert and cuttingassembly provides for the improved delivery of coolant to the interfacebetween the milling insert and the workpiece (i.e., the insert-chipinterface, which is the location on the workpiece where the chip isgenerated). By doing so, the present cutting insert and cutting assemblyprovides for enhanced delivery of coolant to the insert-chip interfaceso as to result in enhanced lubrication at the insert-chip interface.The consequence of enhanced lubrication at the insert-chip interface isa decrease in the tendency of the chip to stick to the cutting insert,as well as better evacuation of chips from the vicinity of the interfacewith a consequent reduction in the potential to re-cut a chip.

The present cutting insert and cutting assembly achieve factors thatimpact the extent of the coolant delivered to the insert-chip interface.For example, the size of the structure that conveys the coolant to thecutting insert can be a limiting factor on the extent of coolantsupplied to the cutting insert. The present cutting insert and cuttingassembly provide supply holes (coolant ports) that are equal to orlarger than the inlets in the cutting insert to maximize the flow of thecoolant to the cutting insert. The present cutting insert and cuttingassembly provide an arrangement in which two or more coolant channelsconvey coolant to a single discrete cutting location. The presentcutting insert and cutting assembly provide irregular coolant channelsand variable areas of the inlet and the discharge in the cutting insertwhich allow for customization of the coolant delivery. By doing so, onecan provide for a range of diversion angles of the coolant, which canrange between about 10 degrees and about 60 degrees

The present cutting insert and cutting assembly provides manufacturingand performance advantages. There can be advantages in using multiplepieces, which together form the cutting insert. For example, in someinstances a cutting insert formed from a base, which presents thecutting edge, and a core can result in enhanced longevity because onlythe base need to changed after reaching the end of the useful tool life.In such an arrangement, the core is detachably joins (or functions with)to the base whereby the core is re-used when the base wears out. Thebase and core can join together via co-sintering, brazing and/or gluing.Furthermore, the base and core can be tightly compressed against oneanother still maintaining their separate and distinct character. Inaddition, to enhance performance, the base and the core can be from thesame or dissimilar materials depending upon the specific application.

When the preferred specific embodiment of the cutting insert presents around geometry at one or more locations, certain advantages can exist.For example, when the cutting insert has a round geometry at thelocation where multiple components are assembled, the assembly ofmultiple components, e.g., a base and a core, does not need indexing.When the cutting insert is round at the cutting edge, a round cuttinginsert is not handed so it can be used in left, right and neutral. Inprofile turning, up to 50% of the cutting insert can function as thecutting edge.

The cutting insert is also available to engage an anti-rotation feature.

The patents and other documents identified herein are herebyincorporated by reference herein. Other embodiments of the inventionwill be apparent to those skilled in the art from a consideration of thespecification or a practice of the invention disclosed herein. It isintended that the specification and examples are illustrative only andare not intended to be limiting on the scope of the invention. The truescope and spirit of the invention is indicated by the following claims.

1. A metal cutting insert for use in chipforming and material removalfrom a workpiece, the metal cutting insert comprising: a metal cuttinginsert body including a cutting edge having at least one discretecutting location, the metal cutting insert body comprising a base memberand a core member, and the base member having a base rake surface and abase flank surface, and each one of the discrete cutting locationscomprises a discrete portion of a cutting edge formed at theintersection of the base rake surface and the base flank surface, andthe core member containing an aperture for receiving a fastener; themetal cutting insert body further containing a distinct interior coolantpassage communicating with the discrete cutting location; the distinctinterior coolant passage having a coolant passage inlet defining acoolant passage inlet cross-sectional area, a coolant passage dischargedefining a coolant passage discharge cross-sectional area, and an axialcoolant passage length; the distinct interior coolant passage defining acoolant flow cross-sectional area along the axial coolant passage lengththereof; the coolant passage inlet cross-sectional area beingsubstantially the same as the coolant passage discharge cross-sectionalarea; and the geometry of the coolant flow cross-sectional area changingalong the axial coolant passage length.
 2. The metal cutting insertaccording to claim 1 wherein the base member being made from one of thematerials selected from the group consisting of tools steels, cementedcarbides, cermets, and ceramics by a powder metallurgical technique, andthe core member being made from one of the materials selected from thegroup consisting of tools steels, cemented carbides, cermets, andceramics by a powder metallurgical technique.
 3. The metal cuttinginsert according to claim 2 wherein the core member being made from thesame material as the core member.
 4. The metal cutting insert accordingto claim 2 wherein the core member being made from a different materialas the core member.
 5. The metal cutting insert according to claim 1wherein the base member being detachably joined to the core member. 6.The metal cutting insert according to claim 1 wherein the geometry ofthe coolant passage inlet cross-sectional area being different from thegeometry of the coolant passage discharge cross-sectional area.
 7. Themetal cutting insert according to claim 1 wherein the cutting insertbeing received in a pocket of holder wherein the pocket having a coolantport therein, the coolant port having a coolant port cross-sectionalarea, and the coolant inlet cross-sectional area being less than thecoolant port cross-sectional area in the pocket.
 8. A metal cuttingassembly for use in chipforming and material removal from a workpiecewherein a coolant source supplies coolant to the cutting assembly, themetal cutting assembly comprising: a holder comprising a pocket, and thepocket including a flat surface containing a coolant port incommunication with the coolant source wherein the coolant port has acoolant port cross-sectional area; the pocket receiving a cuttinginsert; the metalcutting insert comprising: a cutting insert bodyincluding a cutting edge having at least one discrete cutting locationthe metal cutting insert body comprising a base member and a coremember, and the base member having a base rake surface and a base flanksurface, and each one of the discrete cutting locations comprises adiscrete portion of a cutting edge formed at the intersection of thebase rake surface and the base flank surface, and the core membercontaining an aperture for receiving a fastener; the cutting insert bodyfurther containing a distinct interior coolant passage communicatingwith the discrete cutting location; the distinct interior coolantpassage having a coolant passage inlet defining a coolant passage inletcross-sectional area, a coolant passage discharge defining a coolantpassage discharge cross-sectional area, and an axial coolant passagelength; the distinct interior coolant passage defining a coolant flowcross-sectional area along the axial coolant passage length thereof; thecoolant passage inlet cross-sectional area being substantially the sameas the coolant passage discharge cross-sectional area; and the geometryof the coolant flow cross-sectional area changing along the axialcoolant passage length.
 9. The metal cutting assembly according to claim8 wherein the coolant passage inlet cross-sectional area being smallerthan the coolant port cross-sectional area in the pocket.
 10. The metalcutting assembly according to claim 8 wherein the metal cutting insertbody further containing a second distinct interior coolant passagecommunicating with the discrete cutting location.
 11. The metal cuttingassembly according to claim 10 wherein the second distinct interiorcoolant passage having a second coolant passage inlet defining a secondcoolant passage inlet cross-sectional area, a second coolant passagedischarge defining a second coolant passage discharge cross-sectionalarea, and a second axial coolant passage length; the second distinctinterior coolant passage defining a second coolant flow cross-sectionalarea along the second axial coolant passage length thereof; the secondcoolant passage inlet cross-sectional area being substantially the sameas the second coolant passage discharge cross-sectional area; and thegeometry of the second coolant flow cross-sectional area changing alongthe second axial coolant passage length.
 12. The metal cutting assemblyaccording to claim 10 wherein the metal cutting insert body furthercontaining a third distinct interior coolant passage communicating withthe discrete cutting location.
 13. The metal cutting assembly accordingto claim 12 wherein the third distinct interior coolant passage having athird coolant passage inlet defining a third coolant passage inletcross-sectional area, a third coolant passage discharge defining a thirdcoolant passage discharge cross-sectional area, and a third axialcoolant passage length; the third distinct interior coolant passagedefining a third coolant flow cross-sectional area along the third axialcoolant passage length thereof; the third coolant passage inletcross-sectional area being substantially the same as the third coolantpassage discharge cross-sectional area; and the geometry of the thirdcoolant flow cross-sectional area changing along the third axial coolantpassage length.